Problems of Neutrino Radiation from SN 1987A: 30 Years Later

Abstract

Experimental data obtained by means of underground detectors during the explosion of the SN 1987A supernova on February 23, 1987, are discussed. At that time, such data were being collected by two scintillation detectors—the Soviet–Italian liquid scintillation detector (LSD) in a Mont Blanc tunnel and the Baksan underground scintillation telescope (BUST) of the Institute forNuclear Research (Russian Academy of Sciences)—and two Cherenkov detectors—Kamiokande II (Japan) and the Irvine–Michigan–Brookhaven (IMB) detector (USA). Two key instants in SN 1987A evolution that were accompanied by neutrino signals are highlighted. These were 2:52 UT in LSD and 7:35 UT in the other detectors. A group of studies in which correlations between pulses in the different detectors between 1:45 and 3:45 UT and double pulses in LSD between 5:40 and 10:15 UT were observed are also discussed.